1. Field of the Invention
The present general inventive concept relates to a printing apparatus to prevent printing errors and method thereof, and more particularly, to a printing apparatus to prevent printing errors due to feeding of a recording medium such as paper sheets at a same time, and a method thereof.
2. Description of the Related Art
Printing apparatuses such as printers, copiers, facsimiles, or Multi Function Peripherals (MFP) form an image on a paper sheet using operations such as laser irradiation or ink firing. These printing apparatuses generally include a function of feeding printing paper sheets consecutively.
A printing apparatus separates a sheet of paper at a top of a paper stack placed in a cassette using a paper pickup means such as a pickup roller, and feeds the picked paper to a printing unit. Friction occurs between adjacent paper sheets as the paper sheet is picked up, and if friction is greater between a topmost paper sheet and the paper sheet or paper sheets below the topmost paper than between the topmost paper sheet and the paper pickup means, a paper sheet or paper sheets below the topmost paper are picked up together. This phenomenon will be called “multifeed” in the following description.
FIG. 1 illustrates an example of erroneous printing due to the multifeed problem. Referring to FIG. 1, an image is printed partially on each of a first, second and third printing sheets 10a, 10b and 10c. If this happens, a user needs to dispose of printouts, and reprint the image on new paper sheets. The multifeed also increases costs, as multifeed consumes printing consumables, such as ink, toner and paper sheets.